Automated transaction systems such as automatic banking machines or automated civil affair document issuing machines require user authentication so that only authorized users may access the systems. Every requested service such as deposit/withdrawal of cash or issuance of documents can be securely processed only after the authentication is done.
The user authentication may be performed in various manners. One of the most popular methods is that a user who requests service from an automated transaction system registers his/her own password at an institution to which the automated transaction system belongs and accesses the automated transaction system with the registered password.
Instead of the password, the fingerprint of a user may be utilized to identify the user. In this case, a fingerprint recognition apparatus installed in the automated transaction system performs the user authentication process by comparing an input fingerprint with pre-registered fingerprints.
In the user authentication method using passwords, wherein 4-digit passwords are commonly used, passwords that users can remember are notorious for being easy to determine by clever intruders or hackers. Thus, the password becomes the weakest link in the security chain and such an authentication method does not provide a high level of security.
In the user authentication method using fingerprints, a high degree of security can be ensured. However, the recognition rate of a fingerprint recognition apparatus may vary depending on the operating environment or the state of input fingerprints, which is a drawback to reliable user authentication.